part 1 - core web programming
TRANSCRIPT
iii
Chapter
INTRODUCTION XXXIIIReal Code for Real Programmers xxxiv
How This Book Is Organized xxxv
Conventions xxxviii
About the Web Site xxxix
About the Authors xxxix
ACKNOWLEDGMENTS XLI
Part 1THE HYPERTEXT MARKUP LANGUAGE 2
Chapter 1DESIGNING WEB PAGES WITH HTML 4.0 4
1.1 The HyperText Markup Language 5
1.2 HTML 4.0 and Other HTML Standards 7
1.3 Steps to Publish a Document on the Web 9
Create the Document 9
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Put the Document on the Web 10
Validate the Document 12
1.4 The Basic Structure of HTML Documents 12
HTML Document Template 13
DOCTYPE Declarations 14
1.5 HEAD—High-Level Information About the Page 16
Required HEAD Element 17
Optional HEAD Elements 17
1.6 BODY—Creating the Main Document 22
1.7 Summary 25
ChapTer 2BLOCK-LEVEL ELEMENTS IN HTML 4.0 28
2.1 Headings 30
2.2 Basic Text Elements 32
Basic Paragraphs 32
Paragraphs with White Space Preserved 34
Indented Quotations 35
Addresses 35
2.3 Numbered, Bulleted, and Indented Lists 35
Numbered Lists 36
Bulleted Lists 39
Definition Lists 40
2.4 Tables 41
The Basic Table Structure 42
Defining Table Rows 46
Table Headings and Data Cells 48
Grouping Table Contents 50
2.5 Fill-Out Forms 54
2.6 Miscellaneous Block-Level Elements 54
2.7 Summary 57
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ChapTer 3TEXT-LEVEL ELEMENTS IN HTML 4.0 58
3.1 Physical Character Styles 59
3.2 Logical Character Styles 64
3.3 Specifying Hypertext Links 67
3.4 Embedded Images 70
Animated GIFs 71
The IMG Element 71
3.5 Client-Side Image Maps 75
3.6 Embedding Other Objects in Documents 79
Embedded Applets 80
Embedded Video, Audio, and Other Formats with Plug-ins 82
Embedded ActiveX Controls 83
Embedded Scrolling Text Banners 85
3.7 Controlling Line Breaks 86
3.8 Summary 87
Chapter 4FRAMES 88
4.1 Frame Document Template 90
4.2 Specifying Frame Layout 91
4.3 Specifying the Content of Frame Cells 96
Examples 98
4.4 Targeting Frame Cells 100
Predefined Frame Names 103
4.5 Solving Common Frame Problems 103
Bookmarking Frames 104
Printing Frames 104
Updating Multiple Frame Cells Simultaneously 105
Preventing Your Documents from Being Framed 108
Creating Empty Frame Cells 109
4.6 Inline Frames 109
4.7 Summary 113
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Chapter 5CASCADING STYLE SHEETS 114
5.1 Specifying Style Rules 116
5.2 Using External and Local Style Sheets 118
External Style Sheets 119
The STYLE Element and JavaScript Style Sheets 120
Inline Style Specification 121
5.3 Selectors 121
HTML Elements 122
User-Defined Classes 123
User-Defined IDs 124
Anchor Pseudoclasses 124
5.4 Cascading: Style Sheet Precedence Rules 125
5.5 Font Properties 126
5.6 Foreground and Background Properties 132
5.7 Text Properties 135
5.8 Properties of the Bounding Box 139
Margins 140
Borders 141
Padding 142
Bounding Box Display Types 143
5.9 Images and Floating Elements 143
5.10 List Properties 146
5.11 Standard Property Units 147
Lengths 147
Colors 147
5.12 Layers 148
Specifying Layers with the LAYER and ILAYER Elements 149
Specifying Layers with Style Sheets 153
5.13 Summary 157
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Part 2JAVA PROGRAMMING 158
Chapter 6GETTING STARTED WITH JAVA 160
6.1 Unique Features of Java 162
Java Is Web-Enabled and Network Savvy 162
Java Is Cross-Platform 166
Java Is Simple 168
Java Is Object Oriented 169
Java Is Rich with Powerful Standard Libraries 170
6.2 Myths About Java 171
Java Is Only for the Web 172
Java Is Cross-Platform 172
Java Is Simple 174
Java Is Object Oriented (the One True Way of Programming) 174
Java Is the Programming Language for All Software Development 175
6.3 Java Versions 175
Which Version Should You Use? 177
Whichever Version You Use 177
6.4 Getting Started: Nuts and Bolts 178
Install Java 178
Install a Java-Enabled Browser 179
Bookmark or Install the On-Line Java API 180
Optional: Get an Integrated Development Environment 180
Create and Run a Java Program 181
6.5 Some Simple Java Programs 182
The Basic Hello World Application 182
Command-Line Arguments 183
The Basic Hello World (Wide Web) Applet 183
Applet Customization Parameters 185
6.6 Summary 187
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Chapter 7OBJECT-ORIENTED PROGRAMMING IN JAVA 190
7.1 Instance Variables 191
7.2 Methods 194
7.3 Constructors and the “this” Reference 196
Static Initialization Blocks 199
7.4 Destructors 199
7.5 Overloading 200
7.6 Public Version in Separate File 204
7.7 Javadoc 209
Javadoc Tags 211
Javadoc Command-Line Arguments 213
7.8 Inheritance 216
7.9 Interfaces and Abstract Classes 221
7.10 Packages, Classpath, and JAR Archives 230
The CLASSPATH 233
7.11 Modifiers in Declarations 236
Visibility Modifiers 236
Other Modifiers 238
7.12 Summary 239
Chapter 8BASIC JAVA SYNTAX 242
8.1 Rules of Syntax 243
8.2 Primitive Types 245
Primitive-Type Conversion 247
8.3 Operators, Conditionals, Iteration 248
Arithmetic Operators 248
Conditionals 249
Loops 255
8.4 The Math Class 259
Constants 259
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General-Purpose Methods 259
Trigonometric Methods 261
BigInteger and BigDecimal 261
8.5 Input and Output 263
Printing to Standard Output 263
Printing to Standard Error 265
Reading from Standard Input 265
8.6 Execution of Non-Java Programs 266
8.7 Reference Types 273
Java Argument-Passing Conventions 275
The instanceof Operator 275
8.8 Strings 277
String Methods 278
Constructors 284
8.9 Arrays 284
Two-Step Array Allocation 285
One-Step Array Allocation 286
Multidimensional Arrays 287
8.10 Vectors 288
Constructors 289
Methods 289
8.11 Example: A Simple Binary Tree 291
8.12 Exceptions 296
Basic Form 296
Multiple Catch Clauses 299
The Finally Clause 300
Thrown Exceptions 300
Unchecked Exceptions 302
8.13 Summary 303
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Chapter 9APPLETS AND BASIC GRAPHICS 304
9.1 What Are Applets? 305
9.2 Creating an Applet 306
Template for Applets 307
Template for HTML 307
9.3 An Example Applet 309
Redrawing Automatically 311
Reloading Applets During Development 311
9.4 The Applet Life Cycle 312
9.5 Other Applet Methods 314
9.6 The HTML APPLET Element 320
9.7 Reading Applet Parameters 322
Reading Applet Parameters: An Example 323
9.8 HTML OBJECT Element 326
9.9 The Java Plug-In 328
9.10 Graphical Applications 331
9.11 Graphics Operations 332
Drawing Operations 333
Colors and Fonts 336
Drawing Modes 336
Coordinates and Clipping Rectangles 337
9.12 Drawing Images 337
Loading Applet Images from Relative URLs 338
Loading Applet Images from Absolute URLs 340
Loading Images in Applications 342
9.13 Preloading Images 344
9.14 Controlling Image Loading: Waiting for Images and Checking Status 348
9.15 Summary 355
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Chapter 10JAVA 2: GRAPHICS IN JAVA 2 358
10.1 Getting Started with Java 2D 360
Useful Graphics2D Methods 363
10.2 Drawing Shapes 366
Shape Classes 367
10.3 Paint Styles 371
Paint Classes 372
Tiled Images as Fill Patterns 375
10.4 Transparent Drawing 378
10.5 Using Local Fonts 381
10.6 Stroke Styles 383
Stroke Attributes 384
10.7 Coordinate Transformations 390
Shear Transformations 393
10.8 Other Capabilities of Java 2D 394
10.9 Summary 395
Chapter 11HANDLING MOUSE AND KEYBOARD EVENTS 398
11.1 Handling Events with a Separate Listener 400
Drawing Circles 402
11.2 Handling Events by Implementing a Listener Interface 404
11.3 Handling Events with Named Inner Classes 406
11.4 Handling Events with Anonymous Inner Classes 407
11.5 The Standard Event Listeners 409
11.6 Behind the Scenes: Low-Level Event Processing 415
11.7 A Spelling-Correcting Textfield 418
11.8 A Whiteboard Class 421
A Better Whiteboard 423
11.9 Summary 425
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Chapter 12LAYOUT MANAGERS 426
12.1 The FlowLayout Manager 428
FlowLayout Constructor Options 429
Other FlowLayout Methods 429
12.2 The BorderLayout Manager 430
BorderLayout Constructor Options 432
Other BorderLayout Methods 432
12.3 The GridLayout Manager 433
GridLayout Constructor Options 434
Other GridLayout Methods 435
12.4 The CardLayout Manager 436
CardLayout Constructor Options 440
Other CardLayout Methods 440
12.5 GridBagLayout 441
The GridBagConstraints Object 442
Example 444
GridBagLayout Constructor Options 448
Other GridBagLayout Methods 448
12.6 The BoxLayout Manager 449
BoxLayout Constructor Options 452
Other BoxLayout Methods 453
12.7 Turning Off the Layout Manager 454
12.8 Effective Use of Layout Managers 455
Use Nested Containers 456
Turn Off the Layout Manager for Some Containers 459
Adjust the Empty Space Around Components 461
12.9 Summary 464
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Chapter 13AWT COMPONENTS 466
13.1 The Canvas Class 468
Creating and Using a Canvas 469
Example: A Circle Component 469
13.2 The Component Class 472
13.3 Lightweight Components in Java 1.1 479
13.4 The Panel Class 482
Default LayoutManager: FlowLayout 482
Creating and Using a Panel 483
Example: Using a Panel for Grouping 483
13.5 The Container Class 485
13.6 The Applet Class 487
13.7 The ScrollPane Class 487
Creating and Using a ScrollPane 487
Example: ScrollPane with 100-Button Panel 488
13.8 The Frame Class 489
Default LayoutManager: BorderLayout 489
Creating and Using a Frame 490
Frame Examples 491
A Closeable Frame 492
Menus 493
Other Useful Frame Methods 495
13.9 Serializing Windows 497
Writing a Window to Disk 497
Reading a Window from Disk 497
Example: A Saveable Frame 498
13.10 The Dialog Class 501
Creating and Using a Dialog 501
Example: A Quit Confirmation Dialog 502
13.11 The FileDialog Class 504
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Example: Displaying Files in a TextArea 504
13.12 The Window Class 507
Default LayoutManager: BorderLayout 507
Creating and Using a Window 507
13.13 Handling Events in GUI Controls 508
Decentralized Event Processing 509
Centralized Event Processing 511
13.14 The Button Class 512
Constructors 513
Example: Applet with Three Buttons 513
Other Button Methods 514
Handling Button Events 515
13.15 The Checkbox Class 518
Constructors 519
Example: Checked Checkboxes 519
Other Checkbox Methods 520
Handling Checkbox Events 521
13.16 Check Box Groups (Radio Buttons) 521
Constructors 522
Example: Check Boxes vs. Radio Buttons 522
Other CheckboxGroup and Checkbox Methods 523
Handling CheckboxGroup Events 524
13.17 Choice Menus 524
Constructor 525
Example: Simple Choices 525
Other Choice Methods 526
Handling Choice Events 527
13.18 List Boxes 529
Constructors 529
Example: Single and Multiple List Selections 529
Other List Methods 531
Handling List Events 533
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13.19 The TextField Class 538
Constructors 538
Example: Creating TextFields 539
Other TextField Methods 539
Handling TextField Events 542
13.20 The TextArea Class 543
Constructors 543
Example: Empty and Filled Text Areas 544
Other TextArea Methods 544
Handling TextArea Events 545
13.21 The Label Class 545
Constructors 546
Example: Four Different Labels 546
Other Label Methods 547
Handling Label Events 548
13.22 Scrollbars and Sliders 550
Constructors 550
Example: Variety of Sliders 551
Other Scrollbar Methods 552
Handling Scrollbar Events 554
13.23 Pop-up Menus 556
Constructors 556
Example: Applet Pop-up Menu 556
Other PopupMenu Methods 558
Handling PopupMenu Events 559
13.24 Summary 560
Chapter 14BASIC SWING 562
14.1 Getting Started with Swing 564
Differences Between Swing and the AWT 564
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14.2 The JApplet Component 572
14.3 The JFrame Component 574
14.4 The JLabel Component 576
New Features: Images, Borders, and HTML Content 576
JLabel Constructors 577
Useful JLabel Methods 578
14.5 The JButton Component 581
New Features: Icons, Alignment, and Mnemonics 581
HTML in Button Labels 582
JButton Constructors 582
Useful JButton (AbstractButton) Methods 582
14.6 The JPanel Component 585
JPanel Constructors 585
New Feature: Borders 585
Useful BorderFactory Methods 586
14.7 The JSlider Component 590
New Features: Tick Marks and Labels 590
JSlider Constructors 590
Useful JSlider Methods 591
14.8 The JColorChooser Component 594
Constructors 595
Useful JColorChooser Methods 595
14.9 Internal Frames 598
JInternalFrame Constructors 598
Useful JInternalFrame Methods 598
14.10 The JOptionPane Component 602
Useful JOptionPane Methods 602
14.11 The JToolBar Component 607
JToolBar Constructors 609
Useful JToolBar Methods 609
14.12 The JEditorPane Component 614
Following Hypertext Links 615
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JEditorPane Constructors 616
Useful JEditorPane Methods 616
Implementing a Simple Web Browser 618
HTML Support and JavaHelp 621
14.13 Other Simple Swing Components 622
The JCheckBox Component 622
The JRadioButton Component 623
The JTextField Component 625
The JTextArea Component 625
The JFileChooser Component 625
14.14 Summary 626
Chapter 15ADVANCED SWING 628
15.1 Using Custom Data Models and Renderers 630
15.2 JList 631
JList with a Fixed Set of Choices 631
JLists with Changeable Choices 636
JList with Custom Data Model 639
JList with Custom Renderer 646
15.3 JTree 650
Simple JTree 650
JTree Event Handling 654
15.4 JTable 664
Simple JTable 664
Table Data Models 669
Table Cell Renderers 674
Table Event Handling 676
15.5 Swing Component Printing 680
Printing Basics 681
The Role of Double Buffering 683
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A General-Purpose Component-Printing Routine 684
Printing in JDK 1.3 689
15.6 Swing Threads 691
SwingUtilities Methods 693
15.7 Summary 696
Chapter 16CONCURRENT PROGRAMMING WITH JAVA THREADS 698
16.1 Starting Threads 700
Mechanism 1: Put Behavior in a Separate Thread Object 700
Mechanism 2: Put Behavior in the Driver Class, Which Must Implement Runnable 703
16.2 Race Conditions 706
16.3 Synchronization 709
Synchronizing a Section of Code 709
Synchronizing an Entire Method 710
Common Synchronization Bug 710
16.4 Creating a Multithreaded Method 712
16.5 Thread Methods 717
Constructors 718
Constants 719
Methods 719
Stopping a Thread 725
16.6 Thread Groups 727
Constructors 727
Methods 727
16.7 Multithreaded Graphics and Double Buffering 729
Redraw Everything in paint 730
Implement the Dynamic Part as a Separate Component 734
Have Routines Other Than paint Draw Directly 735
Override update and Have paint Do Incremental Updating 737
Use Double Buffering 743
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16.8 Animating Images 748
16.9 Timers 753
Constructor 757
Other Timer Methods 757
16.10 Summary 759
Chapter 17NETWORK PROGRAMMING 760
17.1 Implementing a Client 762
Example: A Generic Network Client 765
17.2 Parsing Strings by Using StringTokenizer 768
The StringTokenizer Class 768
Constructors 769
Methods 769
Example: Interactive Tokenizer 770
17.3 Example: A Client to Verify E-Mail Addresses 771
17.4 Example: A Network Client That Retrieves URLs 774
A Class to Retrieve a Given URI from a Given Host 775
A Class to Retrieve a Given URL 777
UrlRetriever Output 778
17.5 The URL Class 779
Reading from a URL 779
Other Useful Methods of the URL Class 781
17.6 WebClient: Talking to Web Servers Interactively 783
17.7 Implementing a Server 791
Example: A Generic Network Server 793
Connecting NetworkClient and NetworkServer 797
17.8 Example: A Simple HTTP Server 797
ThreadedEchoServer: Adding Multithreading 802
17.9 RMI: Remote Method Invocation 804
Steps to Build an RMI Application 805
A Simple Example 806
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A Realistic Example: A Server for Numeric Integration 811
A Realistic Example of the Four Required Classes 813
Compiling and Running the System for the Realistic Example 817
Enterprise RMI Configuration 819
Compiling and Running the System for an Enterprise RMI Configuration 822
RMI Applet Example 825
17.10 Summary 828
Part 3SERVER-SIDE PROGRAMMING 830
Chapter 18HTML FORMS 832
18.1 How HTML Forms Transmit Data 833
18.2 The FORM Element 838
18.3 Text Controls 843
Textfields 843
Password Fields 845
Text Areas 846
18.4 Push Buttons 848
Submit Buttons 849
Reset Buttons 852
JavaScript Buttons 853
18.5 Check Boxes and Radio Buttons 854
Check Boxes 854
Radio Buttons 855
18.6 Combo Boxes and List Boxes 857
18.7 File Upload Controls 860
18.8 Server-Side Image Maps 862
IMAGE—Standard Server-Side Image Maps 863
ISMAP—Alternative Server-Side Image Maps 865
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18.9 Hidden Fields 867
18.10 Grouping Controls 868
18.11 Tab Order Control 870
18.12 Summary 871
Chapter 19SERVER-SIDE JAVA: SERVLETS 872
19.1 The Advantages of Servlets Over “Traditional” CGI 874
Efficient 874
Convenient 875
Powerful 875
Portable 875
Secure 876
Inexpensive 876
19.2 Server Installation and Setup 876
Obtain Servlet and JSP Software 877
Bookmark or Install the Servlet and JSP API Documentation 878
Identify the Classes to the Java Compiler 878
Package Your Classes 879
Configure the Server 879
Compile and Install Your Servlets 879
Invoke Your Servlets 880
19.3 Basic Servlet Structure 880
A Servlet That Generates Plain Text 882
A Servlet That Generates HTML 883
Simple HTML-Building Utilities 885
19.4 The Servlet Life Cycle 887
The init Method 887
The service Method 888
The doGet, doPost, and doXxx Methods 889
The SingleThreadModel Interface 889
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The destroy Method 890
19.5 An Example Using Initialization Parameters 890
19.6 The Client Request: Form Data 893
Reading Form Data from CGI Programs 893
Reading Form Data from Servlets 894
Example: Reading Three Explicit Parameters 894
Filtering Query Data 897
19.7 The Client Request: HTTP Request Headers 898
Reading Request Headers from Servlets 899
Example: Making a Table of All Request Headers 900
HTTP 1.1 Request Headers 903
Sending Compressed Web Pages 906
19.8 The Servlet Equivalent of the Standard CGI Variables 908
19.9 The Server Response: HTTP Status Codes 911
Specifying Status Codes 912
HTTP 1.1 Status Codes 913
A Front End to Various Search Engines 919
19.10 The Server Response: HTTP Response Headers 924
Setting Response Headers from Servlets 924
HTTP 1.1 Response Headers 926
Persistent Servlet State and Auto-Reloading Pages 932
19.11 Cookies 941
Benefits of Cookies 942
Some Problems with Cookies 943
The Servlet Cookie API 944
Examples of Setting and Reading Cookies 947
Basic Cookie Utilities 951
Finding Cookies with Specified Names 951
Creating Long-Lived Cookies 953
19.12 Session Tracking 953
The Need for Session Tracking 953
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The Session Tracking API 955
Terminating Sessions 959
A Servlet Showing Per-Client Access Counts 960
19.13 Summary 962
Chapter 20JAVASERVER PAGES 964
20.1 JSP Overview 965
20.2 Advantages of JSP 967
Versus Active Server Pages (ASP) or ColdFusion 967
Versus PHP 967
Versus Pure Servlets 967
Versus Server-Side Includes (SSI) 968
Versus JavaScript 968
20.3 JSP Scripting Elements 968
Expressions 969
Scriptlets 972
Declarations 975
Predefined Variables 977
20.4 The JSP page Directive 979
The import Attribute 979
The contentType Attribute 982
The isThreadSafe Attribute 983
The session Attribute 984
The buffer Attribute 984
The autoflush Attribute 984
The extends Attribute 985
The info Attribute 985
The errorPage Attribute 985
The isErrorPage Attribute 985
The language Attribute 985
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XML Syntax for Directives 986
20.5 Including Files and Applets in JSP Documents 986
The include Directive: Including Files at Page Translation Time 987
Including Files at Request Time 989
Including Applets for the Java Plug-In 992
The jsp:fallback Element 995
20.6 Using JavaBeans with JSP 999
Basic Bean Use 1001
Example: StringBean 1003
Setting Bean Properties 1005
Sharing Beans 1011
20.7 Defining Custom JSP Tags 1015
The Components That Make Up a Tag Library 1015
Defining a Basic Tag 1019
Assigning Attributes to Tags 1022
Including the Tag Body 1026
Optionally Including the Tag Body 1031
Manipulating the Tag Body 1034
Including or Manipulating the Tag Body Multiple Times 1038
Using Nested Tags 1042
20.8 Integrating Servlets and JSP 1049
Forwarding Requests 1049
Example: An On-Line Travel Agent 1053
Forwarding Requests From JSP Pages 1062
20.9 Summary 1062
Chapter 21USING APPLETS AS FRONT ENDS TO SERVER-SIDE PROGRAMS 1064
21.1 Sending Data with GET and Displaying the Resultant Page 1066
21.2 A Multisystem Search Engine Front End 1067
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21.3 Using GET and Processing the Results Directly (HTTP Tunneling) 1071
Reading Binary or ASCII Data 1072
Reading Serialized Data Structures 1073
21.4 A Query Viewer That Uses Object Serialization and HTTP Tunneling 1075
21.5 Using POST and Processing the Results Directly (HTTP Tunneling) 1083
21.6 An Applet That Sends POST Data 1086
21.7 Bypassing the HTTP Server 1091
21.8 Summary 1091
Chapter 22JDBC 1092
22.1 Basic Steps in Using JDBC 1094
Load the Driver 1094
Define the Connection URL 1095
Establish the Connection 1096
Create a Statement 1096
Execute a Query 1097
Process the Results 1097
Close the Connection 1098
22.2 Basic JDBC Example 1098
22.3 Some JDBC Utilities 1105
22.4 Applying the Database Utilities 1114
22.5 An Interactive Query Viewer 1120
Query Viewer Code 1122
22.6 Prepared Statements (Precompiled Queries) 1127
22.7 Summary 1131
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Chapter 23XML PROCESSING WITH JAVA 1132
23.1 Parsing XML Documents with DOM Level 2 1134
Installation and Setup 1134
Parsing 1135
23.2 DOM Example: Representing an XML Document as a JTree 1137
23.3 Parsing XML Documents with SAX 2.0 1149
Installation and Setup 1149
Parsing 1150
23.4 SAX Example 1: Printing the Outline of an XML Document 1152
23.5 SAX Example 2: Counting Book Orders 1158
23.6 Transforming XML with XSLT 1164
Installation and Setup 1164
Translating 1165
23.7 XSLT Example 1: XSLT Document Editor 1169
23.8 XSLT Example 2: Custom JSP Tag 1179
23.9 Summary 1187
Part 4JAVASCRIPT 1188
Chapter 24JAVASCRIPT: ADDING DYNAMIC CONTENT TO WEB PAGES 1190
24.1 Generating HTML Dynamically 1193
Compatibility with Multiple Browsers 1197
24.2 Monitoring User Events 1198
24.3 Mastering JavaScript Syntax 1200
Dynamic Typing 1201
Function Declarations 1201
Objects and Classes 1202
Arrays 1208
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24.4 Using JavaScript to Customize Web Pages 1209
Adjusting to the Browser Window Size 1209
Determining Whether Plug-Ins Are Available 1213
24.5 Using JavaScript to Make Pages Dynamic 1215
Modifying Images Dynamically 1215
Moving Layers 1223
24.6 Using JavaScript to Validate HTML Forms 1228
Checking Values Individually 1229
Checking Values When Form Is Submitted 1231
24.7 Using JavaScript to Store and Examine Cookies 1237
24.8 Using JavaScript to Interact with Frames 1242
Directing a Particular Frame to Display a URL 1242
Giving a Frame the Input Focus 1246
24.9 Accessing Java from JavaScript 1246
Calling Java Methods Directly 1247
Using Applets to Perform Operations for JavaScript 1248
Controlling Applets from JavaScript 1252
24.10 Accessing JavaScript from Java 1256
Example: Matching Applet Background with Web Page 1259
Example: An Applet That Controls HTML Form Values 1260
Methods in the JSObject Class 1271
24.11 Summary 1272
Chapter 25JAVASCRIPT QUICK REFERENCE 1274
25.1 The Array Object 1275
Constructors 1275
Properties 1276
Methods 1276
Event Handlers 1279
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25.2 The Button Object 1279
Properties 1279
Methods 1280
Event Handlers 1280
25.3 The Checkbox Object 1281
Properties 1281
Methods 1282
Event Handlers 1282
25.4 The Date Object 1283
Constructors 1283
Properties 1283
Methods 1283
Event Handlers 1286
25.5 The Document Object 1286
Properties 1286
Methods 1288
Event Handlers 1289
25.6 The Element Object 1289
Properties 1289
Methods 1290
Event Handlers 1291
25.7 The FileUpload Object 1291
Properties 1292
Methods 1292
Event Handlers 1292
25.8 The Form Object 1293
Properties 1293
Methods 1293
Event Handlers 1294
25.9 The Function Object 1294
Constructor 1294
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Properties 1295
Methods 1295
Event Handlers 1295
25.10 The Hidden Object 1296
Properties 1296
Methods 1296
Event Handlers 1296
25.11 The History Object 1296
Properties 1297
Methods 1297
Event Handlers 1297
25.12 The Image Object 1297
Constructor 1298
Properties 1298
Methods 1299
Event Handlers 1299
25.13 The JavaObject Object 1300
25.14 The JavaPackage Object 1300
25.15 The Layer Object 1300
Constructors 1300
Properties 1301
Methods 1302
Event Handlers 1303
25.16 The Link Object 1304
Properties 1304
Methods 1305
Event Handlers 1305
25.17 The Location Object 1306
Properties 1306
Methods 1307
Event Handlers 1307
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25.18 The Math Object 1307
Properties 1307
Methods 1308
Event Handlers 1310
25.19 The MimeType Object 1310
Properties 1311
Methods 1311
Event Handlers 1311
25.20 The Navigator Object 1311
Properties 1311
Methods 1314
Event Handlers 1314
25.21 The Number Object 1314
Constructor 1315
Properties 1315
Methods 1315
Event Handlers 1317
25.22 The Object Object 1317
Constructors 1318
Properties 1318
Methods 1318
Event Handlers 1319
25.23 The Option Object 1319
Constructors 1319
Properties 1319
Methods 1320
Event Handlers 1320
25.24 The Password Object 1320
Properties 1320
Methods 1321
Event Handlers 1321
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Contents xxxi
25.25 The Plugin Object 1322
Properties 1322
Methods 1322
Event Handlers 1322
25.26 The Radio Object 1323
Properties 1323
Methods 1323
Event Handlers 1324
25.27 The RegExp Object 1324
Constructors 1324
Properties 1326
Methods 1327
Event Handlers 1328
Special Patterns in Regular Expressions 1328
25.28 The Reset Object 1329
Properties 1330
Methods 1330
Event Handlers 1330
25.29 The Screen Object 1331
Properties 1331
Methods 1332
Event Handlers 1332
25.30 The Select Object 1332
Properties 1333
Methods 1334
Event Handlers 1334
25.31 The String Object 1335
Constructor 1335
Properties 1335
Methods 1335
Event Handlers 1340
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xxxii Contents
25.32 The Submit Object 1340
Properties 1340
Methods 1341
Event Handlers 1341
25.33 The Text Object 1342
Properties 1342
Methods 1342
Event Handlers 1343
25.34 The Textarea Object 1343
Properties 1344
Methods 1344
Event Handlers 1344
25.35 The Window Object 1345
Properties 1345
Methods 1349
Event Handlers 1354
An Example of the open Method 1355
25.36 Summary 1358
INDEX 1360
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xxxiii
Chapter
In late 1995, Marty Hall proposed a new course for the part-time graduate programin Computer Science at the Johns Hopkins University. The idea was to bring togetherthe major Web-related topics in a single course dubbed “Distributed Developmenton the World Wide Web,” with Java technology as a unifying theme. Students wouldlook at HTML, Java, HTTP, CGI programming, and JavaScript, with lots of hands-onprojects and no exams. Little did Marty know what he was getting himself into. Bythe time the first section was offered in the summer of 1996, the Java tidal wave hadswept through the university and the companies that the students represented.Shortly after enrollment opened, the class was filled. There were more students onthe waiting list than in the course. Marty got frantic phone calls from students insist-ing that they absolutely had to be in the course. Several local companies called, ask-ing for on-site courses. What fun!
However, when Marty went shopping for texts over the next semester or two, hegot a rude surprise. Despite the availability of good books in most of the individualareas he wanted to cover, Marty found that he needed three, four, or even five sepa-rate books to get good coverage of the overall material. Similarly, for his day job,Marty was constantly switching back and forth among the best of the huge stack ofbooks he had accumulated and various on-line references. Surely there was a betterway. Shouldn’t it be possible to fit 85 percent of what professional programmers usein about 35 percent of the space, and get it all in one book?
That was the genesis of the first edition of Core Web Programming. The book wasvery popular, but the industry has been rapidly moving since the book’s release.Browsers moved from HTML 3.2 to 4.0. The Java 2 platform was released, providinggreatly improved performance and graphics libraries suitable for commercial-quality
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xxxiv Introduction
applications. JSP 1.0 came along, resulting in an explosion of interest in both servletsand JSP as an alternative to CGI and to proprietary solutions like ASP and Cold-Fusion. XML burst upon the scene. The server equalled or even surpassed the desk-top as the biggest application area for the Java programming language.
Wow. And demand has only been growing since then. Although readers wereclamoring for a new edition of the book, it was just too much for Marty to handlealone. Enter Larry Brown, with broad development and teaching experience in Javaand Web technologies, and with particular expertise in the Java Foundation Classes,multithreaded programming, RMI, and XML processing with Java. Larry teamed upwith Marty to totally update the existing material to HTML 4, CSS/1, HTTP 1.1, andthe Java 2 platform; to replace the CGI sections with chapters on servlets 2.2 and JSP1.1; and to add completely new sections on Swing, Java 2D, and XML processingwith JAXP, DOM Level 2, SAX 2.0, and XSLT. They even got a little bit of sleep alongthe way.
We—Marty and Larry—hope you find the result enjoyable and useful!
Real Code for Real Programmers
This book is aimed at serious software developers. If you are looking for a book thatshows you how to use a browser, lists the current hottest Web sites, and pontificatesabout how Web-enabled applications will revolutionize your business, you’ve come tothe wrong place. If you’re already a programmer of some sort and want to get startedwith HTML, XML, Java applets, desktop applications in Java, servlets, JavaServerPages, and JavaScript as quickly as possible, this is the book for you. We illustrate themost important approaches and warn you of the most common pitfalls. To do so, weinclude plenty of working code: over 250 complete Java classes, for instance. We tryto give detailed examples of the most important and frequently used features, sum-marize the lesser-used ones, and refer you to the API (available on-line) for a few ofthe rarely used ones.
DILBERT © UFS. Reprinted by permission
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Introduction xxxv
A word of caution, however. Nobody becomes a great developer just by reading.You have to write some real code too. The more, the better. In each chapter, we sug-gest that you start by making a simple program or a small variation of one of theexamples given, then strike off on your own with a more significant project. Skim thesections you don’t plan on using right away, then come back when you are ready to trythem out.
If you do this, you should quickly develop the confidence to handle the real-worldproblems that brought you here in the first place. You should be able to balance thedemand for the latest features in Web pages with the need for multiplatform support.You should be comfortable with frames, style sheets, and layered HTML. You shouldbe able to make portable stand-alone graphical applications. You should have noqualms about developing Web interfaces to your corporate database through JDBC.You should be able to connect these applications to remote systems over the network.You should understand how to easily distribute computation among multiple threads,or even spin it off to separate systems by using RMI. You should be able to decidewhere servlets apply well, where JSP is better, and where a combination is best. Youshould understand HTTP 1.1 well enough to use its capabilities to enhance the effec-tiveness of your pages. You should be able to spin off complex server-side behaviorsinto JavaBeans components or custom JSP tag libraries. You should be able to useJavaScript to validate HTML forms or to animate Web pages. You should get a raise.A big one, preferably.
How This Book Is Organized
This book is divided into four parts: HTML, Java programming, server-side program-ming, and JavaScript.
Part 1: The HyperText Markup LanguageWeb pages are created with HTML, the HyperText Markup Language. HTML lets you mix regular text with special tags that describe the content, layout, or appearance of the text. These tags are then used by Web browsers like Netscape Navigator or Microsoft Internet Explorer to format the page. This first part of the book covers the following topics in HTML.
• HTML 4.01. Full coverage of all the elements in the latest official HTML standard. Hypertext links, fonts, images, tables, client-side image maps, and more.
• Major Netscape and Internet Explorer extensions. Forwarding pages, using custom colors and font faces, embedding audio, video, and ActiveX components.
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xxxvi Introduction
• Frames. Dividing the screen into rectangular regions, each associated with a separate HTML document. Borderless frames. Floating frames. Targeting frame cells from hypertext links.
• Cascading style sheets. Level-one style sheets for customizing fonts, colors, images, text formatting, indentation, lists, and more.
Part 2: Java ProgrammingJava is a powerful general-purpose programming language that can be used to create stand-alone programs as well as ones that are embedded in Web pages. The following Java topics are covered.
• Unique features of Java. What’s different about Java? The truth about Java myths and hype.
• Object-oriented programming in Java. Variables, methods, constructors, overloading, and interfaces. Modifiers in class declarations. Packages, the CLASSPATH, and JAR files.
• Java syntax. Primitive types, operators, strings, vectors, arrays, input/output and the Math class.
• Graphics. Applets. Applications. Drawing, color, font, and clipping area operations. Loading and drawing images. Java Plug-In.
• Java 2D. Creating professional, high-quality 2D graphics. Creating custom shapes, tiling images, using local fonts, creating transparent shapes, and transforming coordinates.
• Mouse and keyboard events. Processing events. Event types, event listeners, and low-level event handlers. Inner classes. Anonymous classes.
• Layout managers. FlowLayout, BorderLayout, GridLayout, CardLayout, GridBagLayout, and BoxLayout. Positioning components by hand. Strategies for using layout managers effectively.
• AWT components. Canvas, Panel, Applet, ScrollPane, Frame, Dialog, FileDialog, and Window. Component and Container. Buttons, check boxes, radio buttons, combo boxes, list boxes, textfields, text areas, labels, scrollbars, and pop-up menus. Saving and loading windows with object serialization.
• Basic Swing components. Building Swing applets and applications. Changing the GUI look and feel. Adding custom borders to components. Using HTML in labels and buttons. Sending dialog alerts for user input. Adding child frames to applications. Building custom toolbars. Implementing a Web browser in Swing.
• Advanced Swing. JList, JTree, and JTable. Using custom data models and renderers. Printing Swing components. Updating Swing components in a thread-safe manner.
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Introduction xxxvii
• Multithreaded programming. Threads in separate or existing objects. Synchronizing access to shared resources. Grouping threads. Multithreaded graphics and double buffering. Animating images. Controlling timers.
• Network programming. Clients and servers using sockets. The URL class. Implementing a generic network server. Creating a simple HTTP server. Invoking distributed objects with RMI.
Part 3: Server-Side ProgrammingPrograms that run on a Web server can generate dynamic content based on client data. Servlets are Java technology’s answer to CGI programming and JSP is Java’s answer to Active Server Pages or ColdFusion. The following server-side topics are discussed.
• HTML forms. Sending data from forms. Text controls. Push buttons. Check boxes and radio buttons. Combo boxes and list boxes. File upload controls. Server-side image maps. Hidden fields. Tab ordering.
• Java servlets. The advantages of servlets over competing technologies. Servlet life cycle. Servlet initialization parameters. Accessing form data. Using HTTP 1.1 request headers, response headers, and status codes. Using cookies in servlets. Session tracking.
• JavaServer Pages (JSP). The benefits of JSP. JSP expressions, scriptlets, and declarations. Using JavaBeans components with JSP. Creating custom JSP tag libraries. Combining servlets and JSP.
• Using applets as servlet front ends. Sending GET and POST data. HTTP tunneling. Using object serialization to exchange high-level data structures between applets and servlets. Bypassing the HTTP server altogether.
• Java Database Connectivity (JDBC). The seven basic steps in connecting to databases. Some utilities that simplify JDBC usage. Formatting a database result as plain text or HTML. An interactive graphical query viewer. Precompiled queries.
• XML processing with Java. Representing an entire XML document by using the Document Object Model (DOM) Level 2. Responding to individual XML parsing events with the Simple API for XML Parsing (SAX) 2.0. Transforming XML with XSLT. Hiding vendor-specific details with the Java API for XML Processing (JAXP).
Part 4: JavaScriptJavaScript is a scripting language that can be embedded in Web pages and interpreted as the pages are loaded. The final part covers the following Java-Script topics.
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xxxviii Introduction
• JavaScript syntax. Fields, methods, functions, strings, objects, arrays, and regular expressions.
• Customizing Web pages. Adapting to different browsers, JavaScript releases, and screen sizes.
• Making pages dynamic. Animating images. Manipulating layers. Responding to user events.
• Validating HTML forms. Checking form entries as they are changed. Checking data when form is submitted.
• Handling cookies. Reading and setting values. The Cookie object.• Controlling frames. Sending results to specific frames. Preventing
documents from being framed. Updating multiple frame cells. Giving frame cells the focus automatically.
• Integrating Java and JavaScript. LiveConnect and the JSObject class.
• JavaScript quick reference. Major classes in JavaScript 1.2. All fields, methods, and event handlers. Document, Window, Form, Element, String, Math, RegExp, and so forth.
Conventions
Throughout the book, concrete programming constructs or program output is pre-sented in a monospaced font. For example, when abstractly describing Java programsthat can be embedded in Web pages, we refer to “applets,” but when we refer toApplet we are talking about the specific Java class from which all applets arederived.
User input is indicated in boldface, and command-line prompts are either generic(Prompt>) or indicate the operating system to which they apply (Unix>). Forinstance, the following indicates that “Some Output” is the result when “javaSomeProgram” is executed.
Prompt> java SomeProgramSome Output
Important standard techniques are indicated by specially marked entries, as in thefollowing example.
Core Approach
Pay particular attention to items in “Core Approach” sections. They indicate techniques that should always or almost always be used.
Notes and warnings are called out in a similar manner.
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Introduction xxxix
About the Web Site
The book has a companion Web site at
http://www.corewebprogramming.com/
This free site includes:
• Documented source code for all examples shown in the book; this code can be downloaded for unrestricted use.
• On-line versions of all HTML pages, Java applets, and JavaScript examples.
• Links to all URLs mentioned in the text of the book.• Information on book discounts.• Reports on Java short courses.• Book additions, updates, and news.• A free Ronco combination paring knife and e-commerce tool. OK,
maybe not.
About the Authors
Marty Hall is a Senior Computer Scientist in the Research and Technology Develop-ment Center at the Johns Hopkins University Applied Physics Lab, where he special-izes in the application of Java and Web technology to customer problems. He alsoteaches Java and Web programming in the Johns Hopkins part-time graduate pro-gram in Computer Science, where he directs the Distributed Computing and WebTechnology concentration areas. When he gets a chance, he also teaches industryshort courses on servlets, JavaServer Pages, and other Java technology areas. He isthe author of Core Servlets and JavaServer Pages and the first edition of Core WebProgramming. Marty can be reached at the following address:
Research and Technology Development CenterThe Johns Hopkins University Applied Physics Laboratory11100 Johns Hopkins RoadLaurel, MD [email protected]
Larry Brown is a Senior Network Engineer at the Naval Surface Warfare Center,Carderock Division, where he specializes in developing and deploying network andWeb solutions in an enterprise environment. He is also a Computer Science facultymember at the Johns Hopkins University, where he teaches server-side program-
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xl Introduction
ming, distributed Web programming, and Java user interface development for thepart-time graduate program in Computer Science. Larry can be reached at the fol-lowing address:
Naval Surface Warfare Center, Carderock Division9500 MacArthur BoulevardWest Bethesda, MD [email protected]
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xli
Many people have helped us out with this book. Without their assistance, we wouldstill be on the fourth chapter. Those that provided valuable technical feedback,pointed out errors, and gave useful suggestions include Don Aldridge, Chris Ben-nett, Camille Bell, Pete Clark, Maria Dimalanta, Nguyen-Khoa Duy, Denise Evans,Amy Karlson, Paul McNamee, Toddi Norum, Walter Pasquinni, Rich Slywczak, BobTinker, and Kim Topley. This book would not be a success without their contribu-tions. Mary Lou “Eagle Eye” Nohr spotted our errant commas, awkward sentences,typographical errors, and grammatical inconsistencies. She improved the resultimmensely. We hope that we learned from her advice. Vanessa Moore produced thefinal version; she did a great job despite our last-minute changes and crazy travelschedules. Ralph Semmel and Julie Wessel both provided supportive work environ-ments and flexible schedules. Greg Doench of Prentice Hall believed in a secondedition and encouraged us to write the book. Thanks to all.
Most of all, I–Marty–thank B.J., Lindsay, and Nathan for their patience with mylong hours and funny schedule. I–Larry–thank Lee for her loving support andpatience while I disappeared to the computer room every weekend.
God has blessed us both with great families.
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